为什么 intent.resolveActivity(getPackageManager()) 返回 null 即使有 Activity 来处理它？

Question

I'm following the Android Codelabs , specifically I'm working on this Codelab with implicit intents.

The Codelab has the following method:

public void openWebsite(View view) {
   String url = mWebsiteEditText.getText().toString();

   Uri webpage = Uri.parse(url);
   Intent intent = new Intent(Intent.ACTION_VIEW, webpage);

   if (intent.resolveActivity(getPackageManager()) != null) {
       startActivity(intent);
   } else {
       Log.d("ImplicitIntents", "Can't handle this intent!");
   }
}

The problem is that the intent.resolveActivity(getPackageManager()) returns null, but if I omit this and just call the startActivity(intent) , it works fine and opens the Uri in Google Chrome.

I'm wondering why intent.resolveActivity(getPackageManager()) returns null, even thought the Uri can be opened in Google Chrome?

The Manifest file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.implicitintents">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

In this case the URL that we want to open comes from EditText field, so we can't use an intent-filter with android:host as described here .

Answer 1

In case you haven't solve the problem yet. I don't know if you are using API level 30, but if you are you should check this new Package visibility restrictions . Package Visibility has changed and apps are no longer able to access the Package Manager directly. You need to add a element in your AndroidManifest file. In your case you would need something like this.

<queries>
    <intent>
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.BROWSABLE" />
        <data android:scheme="https" />
    </intent>
</queries>

Answer 2

I had the same problem. I solved it by adding a request to use the browser in the manifest. Now my manifest file looks like this. Try reading this article .

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.android.quakereport">
<queries>
    <intent>
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.BROWSABLE" />
        <data android:scheme="https" />
    </intent>
</queries>
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".EarthquakeActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

Answer 3

add permission

<uses-permission android:name="android.permission.QUERY_ALL_PACKAGES" />

then add Queries

<queries>
   <intent>
      <action android:name="android.intent.action.VIEW" />
      <data android:scheme="https" />
   </intent>
</queries>

I hope it will solve your problem. you can also check package visibility use cases